Demarcation of fluids in pipe lines



March 10, 1953 F, METCALF 2,631,242

DEMARCATIQN OF'FLUIDS IN PIPE LINES Filed June 16. 1948 TAN/f Patented Mar. 10, 1953 DEMARCATION OF FLUIDS IN PIPE LINES George F. Metcalf, Syracuse, N.

Y., assignor to General Electric Company, a corporation of New York Application June 16, 1948, Serial No. 33,311 3 Claims. (01. 250-435) 1 My invention relates to the demarcation of fluids in pipe lines.

The object of the invention is to provide a method and means for marking fluids in pipe lines whereby the boundary between two fluid bodies flowing in sequence through a pipe line can be located, its movement followed, and the condition of the boundary can be determined.

It is common practice to pipe oil and petroleum products of different grades or types in sequence through a single pipe line, and many attempts have been made to mark the boundary between, for instance, a body of oil of one grade and a body of oil of another grade fiowing through the pipe. Solid or liquid foreign bodies have been introduced at the boundary but with little success, since solid objects tend to lodge at valve, bends or joints in the line, whereas liquids are hard to detect, and since both both solid objects and liquid bodies have characteristics difiering in some respect from those of the oil, they tend to lag or lead the boundary and may mix through large volumes of the oil. In addition, the presence of foreign bodies in the oil may be objectionable.

It is accordingly a broad object of the invention to improve the marking of oil in pipe lines,

and more specifically to provide a method which.

includes the use of a radioactive isotope as a marking means.

The novel features which I believe to be characteristic of my invention are set forth with particularity in the appended claims. My invention itself, however, both as to its organization and method of operation, together with further objects and advantages thereof may best be understood by reference to the following description taken in connection with the accompanying drawing, in the single figure of which is shown an oil pipe line representative of an embodiment of my invention.

The drawing shows a pumping station I for supplying oil, or other liquid, from a selected one of tanks or reservoirs 2 under pressure to a pipe line 3 through which the oil may flow to a desired selected one of remote reservoirs or tanks 4. Pumping station I may, for instance, be located at a refinery or in a liquid storage area, and the tanks 4 may represent tanks on a ship or at a remote refinery or storage area. The connecting pipe 3, of course, may be of any desired length up to many miles. Suitable valves are employed for selecting the desired supply tank 2 from which the liquid material is to be drawn. for re ulating the flow through the pipe line 3, and selecting the desired delivery tank 4% Along the pipe line 3 from the pumping station are shown in order an insertion or injection pump 5, and detecting and indicating devices 6; 1, 8 and 9, which are sensitive to radioactive discharges. Only one of these indicating devices is necessary in accord with one feature of the invention, though more than one may be desired under circumstances to be later described.

Insertion pump or syringe 5 operates in the manner of a medical hypodermic syringe and is arranged so that a liquid may be sucked from a vessel I!) through a check valve ll into a cylinder 12 by withdrawing piston l3 and injected into the pipe line 3 through a check valve I4 against the pressure of the liquid in the line by pushing piston l3 further into the cylinder. The fluid thus supplied in accord with the invention contains a radioactive isotope, the fluid including the isotope thus injected having, in accord with the invention, substantially the same physical properties and characteristics as the liquid into which it is introduced. The injected liquid or fluid may be an oil, soap or miscible compound which contains the radioactive isotope. Accordingly, a discrete volume of the liquid in the pipe line is made to include a radioactive isotope, and the isotope-bearing liquid has little tendency to spread in the liq-' uid already in the line since it has the'same viscosity, weight and other physical characteristics.

If the isotope selected is of the type emitting a substantial amount of gamma radiation, it may be possible to detect the presence of the radioactive portion of the mass of liquid in the line by the use of a detector and indicator 6 located en'- tirely external to the pipe line since gamma radiations are not completely absorbed or shielded by steel or other metal of the type and thickness ordinarily used for pipes. Detector and indicator 6 may comprise a detecting element D, an amplifier A, and a meter M, it being understood that the detecting element is senstitive to gamma radiation.

If, on the other hand, the isotope yields primarily alpha or beta radiation, it will be necessary to provide a window in the pipe line pervious to such radiations. The detector and indicator 1 is arranged to detect alpha or beta radiations reaching the detector element D surrounding a small bypass pipe l5 through which a portion of the pipe line liquid flows. The pipe l5 has a thin wall and is of a material, such as aluminum, which readily passes alpha or beta 3 particles. If the wall is sufiiciently thin, other materials may be found to be satisfactory. Since alpha radiation will not pass through more than a very thin layer of oil, beta or gamma radiations will be usually found more suitable, and it may be necessary to provide thin windowseven for gamma radiations if the wall of the pipe is notsufiicientlypervious thereto.

Indicators 8 and 9 represent "a modified arrangement for detecting alpha or beta particles, two indicators being shown for a purpose later discussed. In this case, the window takes the form of a cup-like indentation 1B in the pipe line wall, the walls of the indentation ['6 being of thin aluminum or other material =pervious'fto the radiation. As a modification of this detector arrangement, the detector element itselfmay be located inside the pipe and suitable electrical connections thereto sealed through thepipe w'alll Each of the indicatorsi B, 1, 8 and 9 are shown as fipmnrising a detector element D, :an-amplifier qrrpulse counter A, and an indiea-ting -meter Eh'edetecton-element D :of indicator' s -may be conveniently arranged forzportable use-:al'ong the pipe :line, whereby the location within "the pipe line-Of the radioactive volume, represented by a shaded :area 11. in the drawing, may be determined at any time. "With this indicator; for gammaradiations, *windowswill,v in most instances, :be; unnecessary: The amplifier" and meter of device 5 maybe" portable with the de= itector or :connecteditliereto through a l-ong'eirtension cord. --Indicators ""l, 8 and 9 are arirangedto" indicate the'presen'ce, and intensity, or radioactivity atthe' windows in the pipe line well; although additional windows may be. "pro- .v-ide'dfas desired;

'Thezusef'of two indicators 8 and '8' with their associated; detectors spaceda-part a 'known distance along'the :line, "as shown in the drawing, permits-a ready determination of the rate of flow 40f the-Jliquid. Thus, the time elapsed between the ocurrenceof a maximum deflection of the meterfiof' indic'ater sand the occurrence of 'a -subsequent maximum deflection of the meter of indicators represents the "time takenby 1'.he'lit.j[uid toifiow between the windews leana the rate of flowvin teeter barrels per minute, knowing the size 0f he ipe, -is' readilycalciilated. To' provide an automatic indication; is 0168K timer I e'ma be arranged as -s how n witli a starting connection to the amplifier of device 8 and a stopping'conmeet-ion "to "the amplifier of device 9. Any cbnvenieiitf-means of'stairtihg and stopping may "be emplb yed. For example, areiay 19 connected forjactuation by the amplifier of device B'inay "be closed when the signal from'the detector D of device- 8 is of a predetermined intensity, to complete energizing circuit for timer [8, and a similarly arranged relay 20 connected for actuation bythe amplifier of device 9 may be used to open the energizing circuit as'the signal in de- "vi'ce' ereaches a similar intensity. The timer 18 "thus recordsthe length of time for the passage betweenwindows I6 of that part of the discrete raiiiactiye volume bf ah emission intensity detennined by the intensity of emission for which the relays are adjusted to respond. The timer may be caiibrated in suitable "units oftime, or it may readdirectly in feet perminute, barrels "per minu'teor the like.

'A modified arrangement for indicating therat'e .Of'ifiOW is..=also:' shown in the drawing. In this alternative arrangementfatiiner 21 is arranged iorstarting'in response to the closure of ":a'switch 22 at the time of insertion of the isotope-bearing liquid by injection pump or syringe 5. The switch is shown positioned soas to be closed by an extension on the operating rod for piston l3, although any convenient arrangement may be employed. Timer 2| starts at the closing of switch 22 and operates until the intensity of radiation train the discrete volumeiof radioactive liquid IT, as i-tpasses'the detector D of device =1, reaches a predetermined intensity to operate a relay 23 "connected for opening in response to a predetermined output voltage from the amplifier of device 1. The timer, accordingly, records the time ztakeniby the volume I! to reach device I after insertion-bythe-syringe a known distance up the pipe line.

My invention is of particular utility in marking the boundary within a pipe line between liquids- 0f diiferent types or qualities that may be caused to flow in the line one after the other. As "an example, if 1 th'erltanks 2 contain 7oil of respectively diil'erent heat unit ratings or different purities; 101 different -viscosit-ies; "or the like, 'oil from one "tank .may- {be pumped into the line :up to a desired volume, rand at theend of-the run of this 'first "type of :oil a small volume pf an isotope of the oil isinjected by the insertion pump-'5. The valves arethen-adjusted to supply oil from' the other of the tanks -2 to the line; :and as the: second-typesof oil follows the" first through the'"-line; theboundary be'tweenthetwo types con- .tains or is marked by the' discrete volume of radioactive isotope [1. As the boundary approaches anyrofthein'dicators-6, 1,8 or 9; themdicators-begin 'toindicate the presence of radioactivity'until, approximately at the bound'aryitself, "a maximum indicationeis obtained. Acer= tain amount of mixing will occur; of course; and this will be 'accomp'anied by -'a -sp'reading of the radioactive portion away from the boundary yielding broader indications on'flthe indicators. The indicators are useful, accordingly, not only in detecting the resence of the boundary, "but giving an indicatic'm'n of the amount or inter mixture of the two types of o'il the-region the boundary. This indication of the degree of intermixture ma be Vry'flseIul, as, for instance; if a row g r aci fuel o'il' is follbw'ed' in thep'ipe line by a high gradeoi'l; a radioaetive isotope of the low grade oil inserted at the boiindaii yand the low grade oiljtself will mi'irwiththe following "high gra eoil at "substantially the -sa-me rate, and-the degree 0f contamination of; 'the' liigh grade-oilat any point will be substantially pro 'portional to the intehsity of 'radioa'ctivi'typreserit at that point. Piiope'r segregation ofthe ons at the remote end of the line'is thus possible Without resort 'to the heretofore common necessity of extracting and testing'samples to determine the extent of'contaminationand in-termikture oi theone oil with the other.

v 'WhileIhave-shown only certainpre fer 'red-embodiments of my invention by way of illustras time, many modifications "will occun'to those skilled'in the art a'nd'I therefore wish to have it understood that I intend, in the appended claims, 5110 cover alljs'uch modifications as fall within the-true spirit and scope of my invention.

What I claim as new and desire to secure "by Letters Patent "or "the United "States is:

1. An arrangementror measuring the rate of flow or a liquid in Fix-pipe *line' comprisin means for inserting into a discrete portion of said liquid, *at a predetermined point'inxsai'd line; a' discrete volume of" a" secondliqu'id containing" aradio active material to be carried by the flow of said liquid, means located externally of said pipe line for later detecting the emission from said second liquid flowing past two predetermined spaced points in said line remote from said first point, and means for measuring the time lapse between the time of said detections at said predetermined spaced points comprising timing means rendered operative in response to detection of said emission at the first of said two points and rendered inoperative in response to detection of said emission at the other of said two points.

2. Apparatus for indicating the rate of flow of liquid in a pipe line comprising means for injecting a discrete volume of second liquid into said line, said volume of liquid having substantially the same density and viscosity as that flowing in said line and including a radioactive substance, a timer, means for starting said timer in response to operation of said first means, means for receiving emissions from said substance at a predetermined distance along said line in the direction of liquid flow from said first means, and means for stopping said timer in response to reception of said emissions of greater than a predetermined intensity.

3. Apparatus for controllably transporting oil from two sources through a common pipe to a receiving point comprising means for causing the oil from said sources to flow successively and continuously in said pipe toward said receiving point, an injecting pump for mixing into at least one of said oils, substantially at the boundary separating said oils, a discrete volume of a material similar in physical characteristics to the oil from at least one of said sources, said material containing a radiation emitting substance, and a radiation detector disposed at least partially within said pipe and separated from the oil only by a thin member penetrable to said radiation, and indicating means external to said pipe responsive to said detector.

GEORGE F. METCALF.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,662,429 Lowry Mar. 3, 1928 2,346,043 Mysels Apr. 4, 1944 2,353,382 Barrett July 11, 1991 2,385,378 Piety Sept. 25, 1945 2,450,265 Wolf Sept. 28, 1948 2,453,456 Piety Nov. 9, 1948 2,487,797 Friedman et a1 Nov. 15, 1949 

